The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. For example, the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE), is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards. Another example of a modern communications system being developed is time division-synchronous code division multiple access (TD-SCDMA).
However, coverage by these new networking technologies, which may comprise packet switched (PS) networks (e.g., an Internet Protocol (IP) Multimedia Subsystem (IMS) capable network), may not be universal as they are deployed. Moreover, as these new PS networks are deployed, they may not initially support all modes of communication. For example, upon initial deployment of a PS network, full IMS support for voice over IP (VoIP) may not be provided by the PS network and accordingly the PS network may not support a voice call. Additionally or alternatively, a mobile terminal connected to a PS network may be configured to engage in certain communications, such as voice calls, via circuit switched services of another network. Accordingly, a mobile terminal connected to a PS network may not be able to engage in a voice call unless transferred to a legacy circuit switched (CS) network configured to support voice calls.